Respective roles of cyclobutane pyrimidine dimers, (6-4)photoproducts, and minor photoproducts in ultraviolet mutagenesis of repair-deficient xeroderma pigmentosum A cells
被引:0
|
作者:
Otoshi, E
论文数: 0引用数: 0
h-index: 0
机构:Kyoto Univ, Ctr Radiat Biol, Sakyo Ku, Kyoto 6068501, Japan
Otoshi, E
Yagi, T
论文数: 0引用数: 0
h-index: 0
机构:Kyoto Univ, Ctr Radiat Biol, Sakyo Ku, Kyoto 6068501, Japan
Yagi, T
Mori, T
论文数: 0引用数: 0
h-index: 0
机构:Kyoto Univ, Ctr Radiat Biol, Sakyo Ku, Kyoto 6068501, Japan
Mori, T
Matsunaga, T
论文数: 0引用数: 0
h-index: 0
机构:Kyoto Univ, Ctr Radiat Biol, Sakyo Ku, Kyoto 6068501, Japan
Matsunaga, T
Nikaido, O
论文数: 0引用数: 0
h-index: 0
机构:Kyoto Univ, Ctr Radiat Biol, Sakyo Ku, Kyoto 6068501, Japan
Nikaido, O
Kim, ST
论文数: 0引用数: 0
h-index: 0
机构:Kyoto Univ, Ctr Radiat Biol, Sakyo Ku, Kyoto 6068501, Japan
Kim, ST
Hitomi, K
论文数: 0引用数: 0
h-index: 0
机构:Kyoto Univ, Ctr Radiat Biol, Sakyo Ku, Kyoto 6068501, Japan
Hitomi, K
Ikenaga, M
论文数: 0引用数: 0
h-index: 0
机构:Kyoto Univ, Ctr Radiat Biol, Sakyo Ku, Kyoto 6068501, Japan
Ikenaga, M
Todo, T
论文数: 0引用数: 0
h-index: 0
机构:Kyoto Univ, Ctr Radiat Biol, Sakyo Ku, Kyoto 6068501, Japan
Todo, T
机构:
[1] Kyoto Univ, Ctr Radiat Biol, Sakyo Ku, Kyoto 6068501, Japan
[2] Kyoto Univ, Grad Sch Med, Dept Dermatol, Kyoto 6068397, Japan
[3] Dept Radiat Genet, Kyoto 6068501, Japan
[4] Nara Med Univ, Radioisotope Ctr, Nara 6348521, Japan
[5] Kanazawa Univ, Fac Pharmaceut Sci, Div Radiat Biol, Kanazawa, Ishikawa 9200934, Japan
The role of UV light-induced photoproducts in initiating base substitution mutation in human cells was examined by determining the frequency and spectrum of mutation in a supF tRNA gene in a shuttle vector plasmid transfected into DNA repair deficient cells (xeroderma pigmentosum complementation group A). To compare the role of two major UV-induced photoproducts, cis-syn cyclobutane-type pyrimidine dimers (CPDs) and pyrimidine (6-4) pyrimidone photoproducts (6-4PPs), each photoproduct was removed from UV-irradiated plasmid by photoreactivation before transfection, Removal of either CPDs or 6-4PPs by in vitro photoreactivation reduced the mutation frequency while keeping the mutation distribution and the predominance of G:C-A:T transitions as UV-irradiated plasmid without photoreactivation, indicating that both cytosine-containing CPDs and 6-4PPs were premutagenic lesions for G:CA:T transitions. On the other hand, A:T-G:C transitions were not recovered from plasmids after the removal of 6-4PPs, whereas this type of mutation occurred at a significant level (11%) after the removal of CPDs, Thus, the premutagenic lesions for the A:T-G:C transition are 6-4PPs. Removal of both CPDs and 6-4PPs resulted in the disappearance of mutational hot spots and random distribution of mutation as observed in unirradiated control plasmids, However, the mutational spectrum of photoreactivated plasmids differed significantly from that of unirradiated plasmids, A characteristic feature is a high portion of A:T-T:A transversions (11%) in the photoreactivated plasmid, This mutation is due to nondipyrimidinic "minor" photoproducts, and the mutation spectrum suggests that TA*, the major photoproduct of thymidylyl-(3'-5')-deoxyadenosine, is the premutagenic lesion for this mutation. This is the first report revealing the distinct mutagenic roles of the major UV photoproducts and "minor" photoproducts by the use of (6-4)photolyase.